Combining circuits



Sept 11, 1951 H. w. KOHLER 2,567,214

COMBINING CIRCUITS Filed Allg.- 20, 1945 two halves of a high-mu double triode.

Patented Sept. 11, 1951 UNITED STATES PATENT OFFICE coMINING CIRCUITS Hans W. Kohler, Washington, D. C. Application August 20, 1945, Serial No. 611,680

(Cl. Z50-27) (Granted under the act of March 3, 1883, as amended April 30, 1928; 370 0. G. 757) 4 Claims.

l `The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

This invention is in electrical apparatus and particularly is a circuit for effectively adding two `electrical-signals.

provide novel electronic means for combining two high frequency mark-space signals.

Other objects will be apparent from a reading' of the following specification and claims.

The single drawing is a schematic diagram of the electronic circuit of my invention.

Referring to the drawing, II] and II represent Elements I and I I are intended to be either on or off during the entire length of a baud and may be a part of or controlled by two Eccles-Jordan circuits. A low-mu double triode, comprising triode sections I 2 and I3, is provided; the intelligence signal is applied to the grid of section I2 and the keying signal to the grid of member I3. It will be understood that corresponding bauds of the two signals will be equal in length, and, commonly, all bauds will be of equal length.

Two suitable tubes may, of course, be used in place of each of the double triodes, and in the description to follow the halves of the two double triodes may be referred to as tubes.

The cathodes of tubes I2 and I3 are connected to the cathodes of tubes ID and II, respectively, and thus the cathode potentials of all tubes are determined essentially by the plate currents of tubes I2 and I3.

Assuming that plate current is flowing in tube I2 while none is flowing in tube I3, the cathode of tube I0 is then at some positive potential with respect to ground, as is the grid of tube I I. The cathode of tube I I is at a smaller positive potential with respect to gro-und due to plate current flowing in the latter tube and through cathode resistor I5 of tube I3. As a result, tube I0 is cut olf while tube I I is conducting, and a certain voltage dropdepending upon the values of the various components of the circuit-is developed across plate resistor I6.

Obviously, if tube I3 is conducting and tube I2v is cut off, tube I I will in turn be cut off while tube I0 will conduct and the voltage drop across resistor I6 will be the same as before. These two conditions represent the addition of an on and an off signal, it being apparent that it makes no difference in the result whether the intelligence signal contains a marking baud and the keying signal a spacing baud during a particular time interval, or vice versa.

Should both tubes I2 and I3 be cut off, this representing a case where both intelligence signal and keying signal contain oil or spacing bauds, the grid-cathode potentials of tubes I0 and II are essentially zero, and the voltage drop across resistor I6 is twice as large as before described. Similarly, when both tubes I2 and I3 are conducting, the grid-cathode potentials of tubes I0 and II are substantially zero.

The expressions mark-space and on-olf, and their elements, have been used interchangeably herein. Generally, of course, an on-off signal is utilized in communications of the nature here involved, but other two-level signals are possible and can be combined following the principles of this invention. In the claims, therefore, the eX- pression mark-space signa or the like should be considered to define all usable two-level signals.

One specific embodiment of the invention has herein been described and shown. Many modifications will suggest themselves, however, to those skilled in the art as, for example, the substitution of pentode tubes for the high-mu triodes IIl-I I. For the true scope of my invention, therefore, reference should be had to the appended claims.

I claim:

l. A circuit of the nature described including a lrst tube and a second tube each tube having a cathode, a plate, and a grid element, a third tube and a fourth tube each having a cathode, means for applying a mark-space signal to said third tube, means for applying another markspace signal to said fourth tube, means connected to all of said tubes for biasing the same to make the said third and fourth tubes conductive responsive to the applied mark-space signals and for making the said first and second tubes conductive responsive to the outputs of said third and fourth tubes, means interconnecting the cathodes of said rst and third tubes and the a cathode,- aplate, andV a gridv element, a third tube and a fourth tube each having a cathode, means for applying a mark-space signal to said third tube, means for applying another mark-Y space signal to said fourth tube, means connected to all of said tubes for biasing the same to make'- the said third and fourth tubes conductive responsive to the applied mark-space signals and for making the said first and second tubes con"- ductive responsive to the outputs of said third and fourth tubes, means interconnecting the cathodes of said rst and'third tubes and the* grid element of said second tube, means for in-Y terconnecting the cathodes of said second and fourth tubes and the grid element of said 'rst tube, al-common plate resistor for said rst and second tubes, and means forl taking the' outputI of the circuit across the said resistor.

3. A circuit of the nature described including' a rst-high-mu triodeV and aV second high-mu triode-a first low-mu triode and a second low-mu triode, means-for supplying a mark-spaceV signal to one'of saidlow-mu triodes, means for supply'-u ing another mark-space signal to the other ofv said low-mu triodes, means connected to all of said triodes for making the said low-mu triodes conductive responsive to said mark-space signals, and the high-mu triodes conductive responsive to said low-mu triodes, means for interconnecting said triodes to maintain at substantially like-potentialsthecathode of one-of said 10W-mu triodesfthe cathode of one of said high-mu trodes, and the grid element of the other of said high-mu triodes, on the one hand, and, on the other hand, the cathode of the other of said lowmu triodes, the cathode of the other of said highmu-triodes, and the grid element of the said one of said high-mu triodes. t

4. A cireuitofthe; nature described including a duplex tube, each half thereof having a cathode, a plate, and a grid element, a common circuit for the platesof said tube, a first means responsive to a mark-spacelsignal for supplying a signal to the cathode of one-half of said tube and the grid element of the other half thereof, a-second means responsive toanother mark-space 'signal for'sup-v ditioning 'said halves of said tube for conduction responsive to said supplied signals. 1

HANSW. KOI-ILER.

No references cited. 

